Oscillograph



.J. W. LEGG New. 5, 1929.

OSCILLOGRAPH 2 Sheets-Sheet Original Filed Oct. 10 1925 \w gw &

IRNEY INVENTOR Ja 9 Wleyy.

WITNESSES: fl MM/ New 5, 3929 J. w. LE G OSCILLOGRAFH Original FiledOct. 10 1925 2 Sheets-Sheet WITNESSES jjV/W Patented Nev. 5, $29

JOSEPH W. LEGG, 0F WILKIN SBURG, PENNSYLVANIA, ASfillIG-NOR I0 WESTERNELEG- 'TEIC d; MANUFACTURING COMPANY,'A CORPORATION OF PENNSYLVANIA.

Application filed October 10, 1925, Serial No. 61,810. Renewed May 13,1929.

My invention relates to osciliographs and particularly to oscillographsof the portable t pe.

It is characteristic of my invention that a galvanometcr deflecting orvibratory system is actuated or deflected in accordance with acharacteristic, as magnitude, of a quantity, either electricalornon-electrical in character.

One object of my invention is to reduce the size and the weight ofportable, visual oscillographs, and to render the same simple, compactand durable in construction, economical to manufacture and effective inoperation.

Another objectof my invention is to provide means by which audio-waves,inay be translated into light vibrations enabling deaf persons tocomprehend sound.

Another object of my invention is to provide means for the translationof electrical. waves into light waves in such manner that they may beutilized in television.

A further object of my invention is to provide an instrument which canoperate by means of a small portable. battery for a source of energy andfor this reason may easily be transported.

The invention is an electric translating instrument comprising a movingcylindrical condensing lens and light shield in a lightand compactoscillograph.

Heretofore, oscillographs have comprised stationary lenses andoscillating mirrors. The image is projected from the stationary lens tothe mirror, from which it is reflected to the focal plane of a viewingmeans. The elongated projection required to include the mirror hasincreased the relative size .of the imageto such magnitude that thelight from the source could not be focused to a point, thus requiring avery strong source of light to give a suliicient'intensity in the imageon the viewing means.

In accordance with my invention, the cylindrical lens is movedtransversely of the vibrating mirror and a lens of relatively greatcurvature is used to bring the pencil of light from the mirror to a.focus in a very small image, thus requiring only a small source oflight.

Figure 1 of the accompanying drawings per part of the oscillograplishowing the moving condensing lens and light shield and the viewing mean1 Fig. 3 is an elevational view of the upper part of the oscillographembodying the movlng condensing lens and light shield.

Fig. 4 is a top view of the moving cylindrical condensing lens and lightshield; and

Fig. 5 is a diagrammatic view of a modified form of my invention.

The device'of my invention comprises, in general, a casing 1, a sourceof light 2, a galvanometer 3, a light shield a, a condensing lens 5 anda viewing means 6.

The casing 1 is constructed of wood, although it may be constructed ofany other suitable material, such as sheet metal or in? sulatingmaterial, and comprises a base plate 7, to which the galvanometer 3 isattached, a front or face plate 8, side panels, 9 and 10, rear-wallportion 11 and a top member 12 which carries a lamp socket for thesource of light 2, viewing means and light shade and condensing lens.The main portions are joined integrally to preclude the ingress oflightand a cover 13 is provided to protect the portions which projectabove the top member 12.

The source of light 2 is provided with 'a. base or socket member whichis carried by the top member 12 and com rises a straightline lightsource for the ga vanometer 3 for a purpose to be hereinafter described.

The galvanometer 3 comprises a fluid-tight, oil-filled casing 14,disposed at the lower portion of the casing 1, containing ahorizon,-ta'lly-disposed galvanometer mirror element 15 in the magnetic field ofa permanent magnet 19; it is located beneath a lens 16, situated in theupper wall of the galvanometer casing. The mirror is mounted on avibrating element 17 which is sus ended over two ivory bridges 18aflixed to t e galvanometer casing 14. The extremities of the vibratinge1e-= ment are attached to terminals 20 that receive the currentcarrying the'actuating pulsations of electricity. An ivory pulley 21sustained by-a spring 22 holds the loop end of the vibrating element andmaintains a constant tension in it, which is governed by the tensionapplied to the spring 22 by a screw 23.

The light shield 4 is a round plate of radius sufficiently large toinclude the condensing lense 5 to be hereinafter described, rotating onashaft 24 which is held by a bearing 25 attached to the top member 12 ofthe casing l. The plate is constructed of brass or any other suitablematerial, preferably heavy in weight. The shaft 24 is fitted, both atthe top and bottom, with pulley wheels 26 The focal length of the lensshould be short in order that the image resulting from the pencilreflected by the galvanometer from the lamp be as small and bright aspracticable.

The viewing means, an eye piece 6 of a usual microscopic type, isdisposed in an opening in, and is afiixed to, the top member 12 ofcasing 1 and is so located that its focal plane conforms to the focalplane of the rotary condensing lens and at such a place in that planethat the reflected light from the galvanometer mirror will strike itwhen the ,light is permitted to passby the condensing lens 5.

A clear glass 28 attached to the lower portion of the viewing means, isdisposed in the focal plane thereof. A properly calibrated scale'isetched on the glass, providing means by which the light waves may bemeasured.

In operation, leads of a circuit carrying audio-waves are attached toterminals 20. The source of light 2 may be supplied with current from asmall portable battery. Rays .of light are emitted from thestraight-line source 2, striking the lens 16 which condenses them on thegalvanometer mirror 15 where they are bent by the oscillations which arein accordance with the audio wave pulsations and reflected back throuhthe lens 16 which .refracts them to a penci and directs them tothe.lig'ht shield 4 in front of the viewing means 6.

When the light shield is rotated by the application of a force to apulley 26 or pulley 27, either by hand or by a motor, the cylindricalcondensing lens is passed through the line of vision of the viewingmeans 6. Rays 15 of light, originating in the straight-line source andreflected from the galvanometer mirror 15, are progressively condensedas a moving point and are thus integrated into a light wave by the eyefocused through the viewing means. By thismeans, there is a visual imageof the audio-wave with each rotation of the condensing lens with thelight. shield.

The speed of rotation of the lens and light shield may be rapid when thelightwaves are uniformly recurrent because they may be superposed uponeach other without distortion but, ifthe light waves are not uniformlyrecurrent, as in the case of most translated audio-waves, then the eyecan behold them only one at a time without confusion. The persistence ofvision of the eye is not substantially greater than fifteen changes persecond; consequently, with irregular waves, the eye could not perceivemore than fifteen images per second without interference, and

the speed of the rotation of the lightshield and lens could not be'morethan fifteen rotations per second.

, If. the frequency of the actuating pulsations desired to be translatedisso great that the above described ap aratus cannot present asufficient number 0 characteristic waves, the adaptation of theinventive idea shown in Fig. 5 provides a means whereby apparentlysimultaneous, non-interfering, multiple waves may be secured.

This modification of my invention comprises, in general, in variation tothe above described elements, a light shield 4 and four cylindricalcondensing lenses 5 and,'in addition, a potentiometer 29, two batteries,30 and 31, a resistor 32 a carbon microphone 33, and a transformer 34.

The light shield 4'is similar to that hereinbefore described but thereare inset init, at right-angle radial positions, four cylindricalcondensing lenses 5, as, hereinabove -described, except that they mayrequire greater length.

The otentiometer 29 comprises a fourstage circular resistor 35 and arotatable brush 36 that is driven synchronously with the rotatable lightshield 4. The normal position of the brush 36 is such that it is inquarterly positions on the circular resistor 35 when a lens 5is passingthrough the focal plane of the viewing means.

The two batteries 30 and 31 are small portable dry batteries, thebattery 30 comprising a small number of cells. and the battery 31comprising a relatively large number of cells. The resistor 32 has manytimes the resistance of the potentiometer 29 and the microphone 33 is oa usual type of carbon microphone. The transformer 34 is anaudio-frequency transformer with fewer turns on the secondary than onthe primary to increase the induced current.

. Three circuits 37, 38 and 39 comprise the elements enumerated. Thecircuit 37 includes the carbon microphone 33, the battery and theprimary coil of the transformer 34 which induces the audio-waves intothe secondary coil with increased current values. The circuit 38includes this secondary coil of "ie transformer 34, the circularresistor 35 and the galvanometer 3. The circuit 39 in eludes thepotentiometer 29, the battery 31, the resistor 32 and the secondary coilof the transformer 34, and is joined to circuit 38 at a galvanometerterminal 20 and the potentiomcter brush 36'; the battery supplies thecurrent in an amount governed to a high degree by the resistor 32 butvaried within limits by the varying resistance of the rotatablepotentiometer 29 which is driven at a synchronous speed with the lightshield by small gears or a belt. This varying current is carried by thecircuit 38 to the galvanometer which is proportionately polarizedthereby. The polarization must be of sufficient magnitude to tilt thegalvanometer mirror 15 far enough to present the multiple images focusedby the multiple lenses 5 in the same manner as hereinbefore describedfor a single lens 5 in parallel non-interfering waves in thevfocal planeof the viewing means 6.

In operation the light shield 4 and the potentiometer brush 36 rotate atsynchronous speeds. A first lens 5 passes the viewing means 6 when thebrush 36 is at its fullresistance position and the minimum current isflowing in the circuit 38. The brush 36 has traversed one-fourth of theresistor 35 by the time a second lens is passing the viewing means, thecurrent in circuit 38 is increased, thus tilting the mirror 15 bypolarization of thegalvanometer. In a similar manner, the galvanometermirror is tilted further as each of the two remaining lenses 5 passesthe viewing means 6.

Thus, the mirror 15 is rocked to displace the rays from the source oflight 2 which it reflects toward the viewing'means. If the light shield4 is rotated with a frequency similar to the persistcncy of vision, fourlight waves are simultaneously visible to an eye focused through theviewing means 6, in parallel, non-interfering positions.

My invention provides a means of trans lating audio-waves into lightwaves vin a. greatly simplified manner, the number of parts is reducedto fewer than the number required by similar instruments in the priorart, the efficiency of the source of light is so increased by theshortened focal length of the condensing lens that a lamp may be usedwhich depends on a small dry battery for its supply of current.

By the invention, a simple, eficient and compact oscilloscope isproduced which is 5 capable of translating audio-waves into light waves.The characteristics of the translated audio-waves of letters andsyllables are so distinct that a trained eye can understand sound bysight. The sensitivity of the human eye is such that it can grasp thecharacteristics of a sound by visualizing one or two of the waves whichmust be repeated dozens of times to arouse sympathetic vibrations of thebones in the ear. By this means, deaf persons may beeducated tounderstand sound by visualization of audio Waves.

My copending application Serial No. 12,928, filed September 13,1928,which is a division'of application Serial No. 752,427, filed Nov.26, 1924, and is assigned to the Westinghouse Electric & ManufacturingCompany, describes and claims apparatus for making a vibrating'beam ofenergy appear as a pluralityof waves.

I claim as my invention:

1. An electric translating instrument comprising viewing means, a sourceof light, movable means for focusing rays of light from said sourcedirectly upon the focal plane of the viewing means, and means forvibrating said rays of light in synchronism with applied electricpulsations.

2. An electric translating instrument comprising viewing means, a sourceof light, rotatable means cooperating therewith for focusing rays oflight from said source directly upon the focal plane of the viewingmeans, and means for vibrating said rays of light in accordance withapplied electric pulsations.

3. The combination in an oscillograph of a source of light, means fordisplacing light rays from said source, viewing means, and rotatablemeans adapted to focus said displaced light rays into multiple images inthe focal plane of said viewing means. 1

4;. The combination with means for passing a beam of light along apredetermined path, of means for deflecting said beam of light inaccordance'with a characteristic of a quantity, viewing means with whichsaid beam of light coacts, and means movable transversely of said pathfor focussing said beam of light substantially as a point of light formovement along a focal plane removed from said viewing means.

5. The combination with means for passing a beam of light along apredetermined path, of means for vibrating said beam of light inaccordance with a varying electrical quantity, a light shield movabletransversely of said path, and a condensing lens carried by said lightshield and movable substantially concentrically with respect to the axisof movement of said light shield.

6. The combination with means for passing a beam of ii ht along apredetermined path, of means or vibrating said beam of light inaccordance with variations in an electrical quantity, a rotatable lightshield means for passing a beam of light to saidsystem and thence alonga predetermined path, means for vibrating sald system in accordance withvariations in an electrical uantit 1 means com risin a luralit of q 3 Po condensing lenses movable in successiontrans,

verselyl of said path and with which said beam of light coacts, andmeans timed with said last-named means for controlling the position ofsaid vibratory system.

8. The combination with galvanometer mechanism including a vibratorysystem, of means for passing a beam of light to said system and thencealong a predetermined path, means for vibrating said system inaccordance with variations in an electrical quantity, rotatable meanscomprising a plurality of condensing lenses movable in successiontransversely of said path and with which said beam of light successivelycoacts, means timed with said-last-named means for controlling theposition of said vibratory system, and viewing means eccentricallypositioned with respect to the axis of said rotatable means.

9. The combination with galvanometer mechanism including a vibratorysystem, of means for passing a beam of light to said system and thencealong a predetermined path, means for vibrating said system inaccordance with variations in an electrical quantity, means comprising aplurality of condensing lenses movable in succession transversely ofsaid path and with which said beam of light coacts, and means timed withsaid last named means for successively and progressively tilting saidvibratory system from its normal position.

10. The combination with galvanometer mechanism including a vibratorysystem, of means for passing a beam of light to said system and thencealong a predetermined path, means for vibrating said system inaccordance with variations in an electrical quantity, means comprising aplurality of,

fleeting mirror occupying a normal selected.

position, means for Vibrating said mirror in accordance with variationsin an electrical quantity, and means for moving and temporarilyretaining said mirror in a position removed fromsaid first-namedposition.

12. The combination with galvanometer tioned in a predetermined plane,means for vibrating said system in accordance with variations in anelectrical quantity, and means for positioning said vibratory system ina plane angular-1y related with respect to said first-named plane.

13. The combination with galvanometer mechanism including a vibratorysystem positioned in a predetermined plane, means for vibrating saidsystem in accordance with variations in an electrical quantity, andmeans for successively and progressively tilting said vibratorysysteminto a plurality of planes each angularly related with respect to saidfirst-named plane.

14. The combination with galvanometer mechanismincluding a vibratorysystem positioned in a predetermined plane, means for vibrating saidsystem in accordance with variations in an electrical quantity, andmeans comprising an electrical circuit ineluding a resistor forsuccessively and progressively tilting said vibratory system from saidfirst-named plane.

15. The combinzmionv with galvanometer mechanism including a vibratorysystem comprising a light-reflectin mirror positioned in a predeterminedplane, of means for vibrating said system by an electrical current andin accordance with variations thereof, and means for positioning saidlight-reflecting mirror in a plane angularly related to said first-namedplane during continuation of the action of said electrical current onsaid vibratory system.

16. The combination with gaivanometer mechanism including a vibratorysystem comprising a ligl1tretlecting mirror positioned in apredetermined plane, of means for vibrating said system by an electricalcurrent and in accordance with variations thereof, and means forsuccessively and progressively tilting said light-reflecting mirror intoa plurality of planes eachangularly related to said first-named planeduring continuation of the action of said electrical current on saidvibratory system. r

17. The combination with galvanometer mechanism including a vibratorysystem positioned in a predetermined plane, of means 'for vibrating saidsystem in accordance with variations in an electrical quantity, andmeans comprising stationary and rotating elements, of an electricalcircuit for successively and progressively tilting said vibratory systemfrom said first-named plane, one of said elements comprising a pluralityof units.

18. The combination with galvanometer mechanism including a vibratorysystem positioned in a predetermined plane,ot means for vibrating saidsystem in accordance with meant? V variations in an electrical quantity,and

- ing a beam of light along a predetermined path, of means fordeflecting said beam of light in accordance with a characteristic of aquantity, means movable transversely of said path for focusing saidlight beam substantially as a point of light for movement alonga planeangularly related with respect to said path, and means for viewing thewave form traced by said point of light, said focusing means moving atsuch high velocity that the wave form appears to persist after passageof-said focusing means from the field of vision of said viewing means. 4

20. The combination with means for pass ing a beam of light along apredetermined path, of means for deflecting said beam of light inaccordance with a characteristic of a quantity, a condensing lensmovable transversely of said path for focusing said lightbeamsubstantially as a point of light for movement along a plane angularlyrelated with respect to said path, and means for viewing the wave formtraced by said point of light, said condensing lens moving at such highvelocity that the wave form appears to persist after passage of saidcondensing lens from the field of vision of said viewing. means.

21'. The combination with means for pass-' ing a beam of light along apredetermined path, of means for vibrating said beam of light inaccordance with a varying electrical quantity, a rotatable light shieldmovable transversely of said path, and a condensing lens carried by saidlight shield.

22. The combination with means for passing a beam of energy along apredetermined path, of means for vibrating said beam of energy inaccordance with a varying electrical quantity, and means for making saidvibrating beam of energy appear as a plurality of waves side by side.

23. Electrical apparatus comprising means for passing a beam of lightalong a predetermined path, means including agalvanometer-deflecting-element for vibrating said beam of light inaccordance with a varying electrical quantity, a receiving means forindicating the vibration of said beam of light, and means for shiftingthe datum or zero of vibration of said reflected beam of light duringthe continuance of the mirror vibrations, whereby a plurality of imagesare produced on the receiving means by one and the same deflectingelement.

24. The combination with means for passing a beam of light along apredetermined path, of means for vibrating said beam of light inaccordance with a varying electrica quantity, viewing means in the pathof said beam of light, and means for making said vibrating beam of lightappear in said viewing means as a pluralityof waves side by side.

. 25. In combination with a single galvanometer-deflecting element and aviewing means, means for altering the character of the currentsentthrough said element at a rate at least as great as the persistency ofhuman vision, and means for impressing the electrical quantity to bestudied upon said element during theintervals between said alterationsin the character of said current.

26. The combination with means for pass-- ing a beam of light along apredetermined path, of means including a galvanometer-defleeting elementfor deflecting said beam of light in accordance with a varyingelectrical quantity, viewing means comprising a plurality of viewingelements, and means for imparting an additional deflection to said beamof light each time one of said viewing elements moves into the path ofsaid beam of light, whereby said beam is brought into a new positioncorresponding to the viewing element just moved into the path of saidbeam of light.

27 .The combination with means for passing a beam of light along apredetermined path, of means including a galvanometerdeflecting elementfor vibrating said beam of light in accordance with a varying electricalquantity,viewing means comprising a plurality of viewing elements, andmeans for passing a diflerent quantity of-direct current through saiddeflecting element each time one of said viewing elements moves into thepath of said beam of light. 28. In electrical apparatus, a circuitcomprising a galvanometer-deflecting element, a circuit including asource of alternating current in series with the said element, and asecond circuit including a source of direct current connected inparallel with a portion of saidfirst named circuit.

29. Electrical apparatus comprising a straight-line source of light,alight shield, a cylindrical lens carried by said light shield, meansfor forming a real image of said light source in a plane near said lightshield, means for deflecting the beam of light which forms said realimage, and means for moving said cylindrical lens through said beam oflight 4 with the axis of said cylindrical lens approxima'tely at rightangles to the plane of said beam of light. I

'In testimony whereof, I have hereunto subscribed my name this 24th dayof September, 1925.

JOSEPH WV. LEGG.

CERTIFICATE OF CORRECTION.

Patent No. 1,734,217. Granted November 5, 1929, to

JOSEPH w. LEGG.

It is herebgr certified that the above numbered patent was erroneouslyissued I to "Western Electric 81 Manufacturing Company, a Corporation ofPennsylvania", whereas said patent should have been issued to"Westinghouse Electric & Manufacturing Company, a Corporation ofPennsylvania" as shownby the records of assignments in this office; andthat the said Letters Patent should be read with this correction thereinthat the same may conform to the record of the casein the Patent Office.

Signed and sealed this 3rd day of December, A. D. 1929.

a M. J. Moore, (Seal) Acting Commissioner of Patents.

